/Engine/Source/Runtime/Engine/Public/MaterialShared.h
[FMaterialFunctionCompileState](API\Runtime\Engine\FMaterialFunctionCompileState) * FindOrAddSharedFunctionState ( [FMaterialExpressionKey](API\Runtime\Engine\FMaterialExpressionKey) & ExpressionKey, class [UMaterialExpressionMaterialFunctionCall](API\Runtime\Engine\Materials\UMaterialExpressionMaterialFunct-) * SharedFunctionCall )